Steering mechanism



Oct. 16, 19282 5. R. w. M. BAGER STEERING MECHANISM v Filed May 2, 1923 s Sheets-Sheet 1 ATTORNEY.

Octlfi, 1928. 1,687,653 s. R. W. M'. BAGER' STEERING MECHANISM Filed Hay 1923 3 Sheets-Sheet 2 ATTORNEY.

I NVEN TOR.

Syn/v 72R WM B/IGER 1 .Q Emu I S. R. W. M. BAGER oci. 16, 1928.

TEERING MECHANISM Filled May 2, 1925 s Sheets-Sheet INVENTOR. J'Wl/VTE A. VK/V. 5x 5? ATTORNEY.

SVANTE B. W. BAGER, OF SOUTH MILWAUKEE, WISCONSIN, AiSSIGNOR T0 BUCYBUS- ERIE COMPANY, OF SOUTH-MILWAUKEE; WISCONSIN, A CORPORATION 0F DELA- a WARE.

STEERING MECHANISM.

Application filed. May 2, 1923 Serial No. 636,137.

This invention relates to steering mechanism for power excavators, cranes and the like, in which the upper or head frame, carrying the operating parts, is revoluble with spect to the base or truck frame.

In machines of this character, direct connections have heretofore been employed between the head frame and. steering axle, in the case of wheel traction, or between the head frame and appropriate clutches on the driving shaft, in the case of creeping trac tion, so that steering movements are depend-' ent upon and responsive to actual rotation of the head frame.

The general aim of the present invention is the provision of steering mechanism which is not dependent for its operation upon actual rotation of the head frame but in which steering is effected by the application of power derived from the mechanism ordinarily employed for rotating the frame.

A more specific object is the provision of steering mechanism which may be made to respond to rotation of the swing pinion ordinarily employed as part of the head frame rotating mechanism.

Another object is the provision of a novel steering mechanism for creepingtraction mechanisms, permitting, assembly of the opcrating parts in readily accessible positions outside of the traction elements.

Other objects and advantages will appear from the following description of several illustrative embodiments of the invention.

In the drawings: i

Figure 1 is a plan view of the truck frame of a. power excavator equipped with a steer.- ing mechanism constructed in accordance with the present invention.

Figure 2 is a view in side elevation, partly in section. of the machine shown in Figure 1.

Figure 3 is a vertical sectional view of a portion of one of the hearing roller supports.-

Figure 8 is a' fragmentary view similar to F gure 7 showing a similar steering mechanism applied to a wheeled truck frame.

A steering mechanism constructed inaccordance with the present invention will first be described as embodied in a power excavator of the creeping traction type. The base or truck frame of a machine of that. type is illustrated in Figures 1 and 2. This frame is of substantially the same construction as that fully described in U. S. Patent No. 1,57et,041 of S. R. W. M. Bager and Werner Lehman. It comprises a pair of longitudinal sidesills 1O rigidly connected with a pair of end bars 11 and a series of transverse intermediate bars 12. The intermediate bars 12 and longitudinal sills 10 constitute a support for a rigid casting 13 in the form of a combined rack and track member for rotatably supporting 'the head frame 14. The casting 18 is provided with a central hub 15 through which the usual vertical propulsion shaft 16 extends and about the axis of which the head frame is permitted to revolve.

The truck frame is supported upon two sets of rollers respectively disposed beyond the sides-0f the frame, each set being disposed to travel upon an endless tread belt 17 trained thereabout. naled upon the ends of an axle 19 adjustably fixed to and beneath the longitudinal sills 10. The rear rollers 20 are provided with belt en- The front rollers 18 are jourgaiing lugs 21 and are driven from the rear axle shaft 22. on which they are mounted, through clutches 23 to be hereinafter described. The shaft 22 is jour-naled in bearings 22 secured'to and beneath the sills 10 and is driven from the vertical propulsion shaft 16 through the usual intermediate" shaft 24 and bevel gear sets 25 and 26. Each of the intermediate rollers 27 is journaled upon the end of a separate stub shaft 28 constituting part of a bracket arm 29 secured intermediate its ends to and beneath a longitudinal sill 10 and fixed at its inner end beneath a transverse bar 12 to tie-bolts 30 extending downwardly from the casting 13 and embracing the bar 12. r The forward pair of bracket arms 29 are preferably hollow for a purpose which wi ll hereinafter appear.

The head frame 14 is rotated about the axis of the shaft 16 'by means of a pinion 31 which normally meshes with a fixed rack 32 extending about the periphery of the casting 13. Pinion 31 is carried by and driven from a vertical shaft 33 journaled in the head instance, the pinion 31 is splined to the'shaft 33,.so as to permit lowering of the of mesh with the fixed rack 32. noted that the plane of the rack 2 is sufficiently elevated above the truck frame to provide the necessary clearance between the extended lower end of the pinion shaft 33 and truck frame, as the head frame revolves.

The steering mechanism shown comprises a lever 34 mounted at one end 35 upon a vertical ivot pin 36 so as to swing in a horizontal p ane about an axis adjacent the pivotal axis of the head frame. Pin 36 is removably fixed in a boss 37,formed on the rear end of a bracket plate 38, secured to and beneath pinion out the forward pair of intermediate transverse bars 12. The lever 34 extends forwardlyand upwardly above the truck frame to a point in advance of the casting 13 and at its upper end 'is provided with a. segmental rack 39 below the plane of the fixed rack 32 sov as to mesh with the swing pinion 31 when lowered out of mesh with the fixed rack.

It willthus be noted that when the pinion '31 is in its normal upper position in mesh with the rack 32, rotation thereof will cause rota- .tion of the head frame 14 in the usual manner. When shifted downwardly along the shaft 33 out of mesh with rack 32 and into mesh with segmental rack 39 rotation, of this pinion will cause the lever 34 to swing laterally in one direction or the other from'its normal neutral position along the central longitudinal axis of the truck frame.

The position of elevation of the pinion 31 ma be determined by any appropriate means un er control of the operator. In the machine shown, this means comprises'ajlever 40 hinged at one endupon a horizontal pivot 41 tolock the head frame against rotation when carried by the head frame and provid ed with a bifurcated portion 42 having the usual pins in rotative engagement with an ,annular groove 43 formedin a collar 44 fixed to the pinion. This lever 40 also preferably carries a finger 45 engageable between the teeth of the rack 32 when the pinion is lowered, so as the pinionis disengaged from the rack 32."

' A link 46 connected with the lever 40 and extendingupwardly through the floor of the head frame into convenient reach of the op erator may be employed for adjusting the lever 40.

A pair of opposite sides of thel'ever 34. Each rod 47 extends loosely through aneye 49 in the forward end of a'lever 50 and at its free end is provided. with a nut 51'and locknut 52 adaptedto bear against this end of lever 50 when t will bev pull rods 47, each extending through one of the hollow bracket arms 29,. are connected at their inner ends 48 to the pivotally connected with a collar 54 rotatably' fixed upon a sleeve 55 forming a part of a clutch element 56, splined upon one end of the rear axle shaft 22.'- Each clutch element 56 is yieldably retained in interlocking engagement with corresponding clutch teeth formed on the face of the adjacent rear roller 20. so that both rear rollers are normally locked to the rear axle shaft 22 so as to rotate therewith. In this instance, this normal closed condition of the clutchesis effected by the provision of coiled compression springs 57 each disposed within one of the forward bracket arms 29. As shown in Figure 3, each spring 57' bears at one end against a sleeve 58 retaine in fixed position within the arm 29 by a stu 59, and at theother end bears outwardly against a movable sleeve 60 which in turn ears against the forward end of the lever the upper frame may be effected in the usual manner by. rotation of the pinion. In order to utilize the swingmechanism for steering purposes, the head frame is first swung into such position that the pinion 31 is above the center of the segmental rack 39 and the pinion 31 then lowered out of mesh with the fixed rack- 32 into mesh with the segmental rack. This is accomplished by depressing the link 46 and thereby forcing the lever 40 downwardly to the dotted line position indicated in Figure 2 in which poistion thetooth 45 on the lever 40 engages between the teeth of the fixed rack 32 to lock the-head frame against rotation. I i As above pointed out, the two clutches cooperating with the rear rollers 20 are normally iii closed condition so that these rollers normally rotate in unison with the rear axle shaft 22, and this shaft being driven from rotation' of the pinion 31 in mesh with the segmental rack 39. For instance, rotation of pinion 31 in a clockwise direction (Fig. 1) causes the segmental rack 39 and lever-34 to swing in a like direction. When this occurs,

the pullrod 47 or? the left side of the machine is drawn inwardly,-tho nut 51 thereon pressing the forward end of the lever 50 inwardly against the pressure of spring 57. and causing the rear end of this lever to swing outwardly so as to withdraw the clutch element 56 out of engagement with the clutch teeth on the corresponding roller 20. In this condition of the parts, this roller is released from driving engagement with the shaft and a driving force is applied to the roller on the right side of the machine only. This obviously results in a turning movement of the machine toward the left. A turning movement in the other direction is similarly effected by a-rotation of the pinion 31 in the opposite direction.

In the machine shown, provision is also made for steering by hand. For this purpose, the upper end of lever 34 carries a forwardly projecting hollow boss 61 adapted to removably but snugly receive the end of a bar 62. This bar may be used as a handle to swing lever 34- in either direction from its neutral position to thus selectively release the clutch substantially in the manner above 'described.

Figures 4 and 5 illustrate a similar type of steering mechanism applied to a power excavator mounted on Wheels. The truck frame of this machine is constructed in substantially the same manner as that hereinabove described. In this instance, however, the front wheels 18' are journaled upon the ends of an axle 19 rockably mounted between the bifurcations 63 of a vertical king pin 63. The pin 63 is journaled in a rigid mounting 64 extending transversely between and rigidly secured at its opposite ends to a pair of plates 65. Plates 65 are secured at their opposite ends to and between the forward transverse bar 11 and the adjacent intermediate transverse bar 12. The rear driving wheels 20 are keyed to the opposite ends of the rear axle shaft-22'. j ournaled beneath the longitudinal sills 10 of the truck frame and driven from the vertical propulsion shaft 16 through the intermediate shaft 24 and appropriate gearing.

The swing pinion 31 is splinedzupon and driven by the shaft 33 so as to be vertically shiftable from in mesh with the fixed rack 32 into mesh with a segmental rack 39 carried by the lever 31. The position of elevation'of this pinion is manually controlled in the manner hereinabove pointed out by the link 16 and lever .40, lever 40 having the finger 45' engageable between the teeth of the-fixed rack 32 when in lower position to lock the head frame 14: against rotation.

The steering lever 34' is mounted at its rear end to swing about a vertical pivot pin 36 mounted in a fixed bracket plate 38 in the manner above described. In this instance, however, a laterally extending crank arm 66 is rigidly secured to the pivoted end of the lever 34. to swing therewith. This crank arm 15 operatively connected to the front axle 19' j through a heavy link 67. The arrangement 7 is such that when the lever 34 1s swung in either direction from a neutral intermediate position, the froniiaxle 19' is swung about the matically lockin axis of the king pin 63 for steering purposes. Manual steering may thus be effected by the use of a bar 62 insertable in the hollow boss 61 carried by the lever 34. For power steering, however, the pini0n-31 is lowered into mesh with the segmental rack 39' so that the lever 3 1, and consequently the front axle may be swung in response to rotation of this pinion.

Provision is preferably made for autothe front axle against horizontal swinging during normal operation of the machine. For this purpose, trip dog 68 is provided pivoted intermediate its ends upon the upper forward end of lever 34'. One end 68 of this dog is provided with a tooth .69, engageable in appropriate grooves 7 0 found in the top face of the mounting 64: so as to releasably lock the lever 34" against swinging. The other end 71 of dog 68 is fashioned to project into the path of vertical movement maintains the dog 68 in looking engagement when the pinion 31 is in upper position in mesh with therack 32. The pinion 31, however, in itsdownward movement into mesh with the segmental rack 39 depresses the end' 71 of the dog and rocks the dog into released position.

In some machines, particularly those of the smaller type in which it is desirable to avoid the increased height of the casting 13 necessitated by the elevation of the rack 32, the steering mechanism may be so designed as to avoid thenecessityof withdraw ng the swing pinion 31 out of mesh with the rack 32. A steering mechanism involving these features for use in machines of the creeping traction tvpe is shown in Figures 6 and. 7, wh le in Figure '8 a steering mechanism for use in a wheeled machine is shown.

In Figures 6 and 7 the steering lever 34, similar to that hereinabove described, carries at its upper end a segmental rack 39 mounted to swing about. ahorizontal pivot pin 75. The. swing pinion 31' is, in this instance, fixed to its driving shaft 33' and is always in mesh with the fixed rack 32'. By swinging the segmental rack about its pivot 75 it may be thrown into or out of meshwith the pinion. The position of the segmentalrack is controlled by a pair of tail pieces 7 6 formed as an integral part thereof and -fashioned to receive a locking pin 7 7. When in the position shown infull lines in F igure 7, the pin 77 engages beneath the boss 61 of the lever 34? and retains the segment 39 in mesh with the pinion. After releasing the pin'77, however, the segment may be rocked into thev dotted position shown, out of mesh with the pinion and retained in such position by reinsertion of the pin in the tail piecesabove the boss 61.

When in pinion engaging position, the segmental rack 39'-,fand consequently the lever 34?, swing in response to rotation of the pinsubstantially as hereinabove'described. The

7 travel of the machine.

. and said driving wheel, actuated by said lever. ing mechanism,

4- 3,687,053" ion to efiecta selective release of the clutdhes 4. In a machine of the character described I the combination of a base frame, a creeping slight rotation of the head frame resulting traction mechanism at each side of said frame,

from the travel of the pinion 31- about the a head frame rotatable on said base frame, a

rack 32, dub to the fact that it is retained in drive shaft operated from said head frame, a

mesh therewith, is not sufficient to materially clutch between each traction mechanism and interfere with the steering operations 0 or 7 said shaft, said clutches being disposed at the outer sides of said traction mechanisms, and

The mechanism shown in Figure 8 is simmeans operated from said head frame between ilar to that just described, except that the segsaid traction mechanisms for controlling said mental rack 39 is mounted on the lever 34 so clutches to steer the machine, said means passas to swing upwardly rather than do-wning through axle members of said traction wardlv from in mesh with the swing pinion mechanism. 31. In this case, the lever 34 is operatively 5. In a machine of the character described, connected with the front steering axle of the the combination of a base frame, a head machine so that swinging of the lever 34 in frame, supported thereby and rotatable with response to rotation of the pinion causes a respect thereto; traction means support-ing corresponding swinging of the front axle. Lthe base Specific claims to the selective feature of framerelative to the base frame, consisting Figure 2 are included in my copending appliin a circular rack carried by the base frame, (iatlOII, Serial No. 128,984, filed August 13, and a rotatable pinion carried by the head Various changes may be made in any of the I several embodiments of the invention hereinout of mesh with said pinion; and means opabove described, without departing from or erated by said rack for steering the machine. sacrificing any of the advantages of the in- '6. Inamachine of the character described, vention as defined in the appended claims. e Combination O a base frame, a hfld I claim: frame, supported thereby and rotatable with 1. In a machine of the character described respect thereto; traction means supporting the combination of a base frame, a creeping the base frame; steering mechanism for said traction mechanism at each side of said frame, traction means; mechanism to swing the head a head frame rotatable on said-base frame, a drive shaft operated from said head frame, clutch between each traction mechanism and and a. rotatable pinion carried by the head said'shaft, said clutches being disposed at the frame and engaging the rack; and means outer sides of said traction mechanisms, and whereby the rotation'of the pinion, while the a line of control for said clutches extending pinion still maintains its engagement with from thehe'ad frame to a point in the base the rack, can at will be used to actuate said frame intermediate the two creeping traction steering mechanism by a series of mechanical mechanisms thence branching and extending operations constituting a chain of causation through axle members of the creeping'trac- W tion mechanism to said clutches, for controlheadframe, 4 ling said clutches to steer the machine. 7. In a machine of the character described, 2. Inacreeping traction unit, the combinathe combination of a' base frame, a head tion of a creeping traction belt, a driving frame, supported thereby and rotatable with wheel for said belt, a phirality of load-susrespect thereto; traction means supporting taining wheels running on'said'belt, shafts the base frame; steering mechanism for said (one of them being hollow) for journally traction means; mechanism to vswing the head mounting said load sustaining wheels, a lever frame relative to the base frame; and means pivoted on one of these shafts and actuated whereby the action of said swing mechanism, by means within the hollow shaft, a drive while still remaining in operative engageshaft, and. a clutch between said drive-shaft ment, can at will be used toactuate said steerotherwise than. through the 3. In a creeping traction unit, the 'combinarotation of the head frame. tion of a creeping tractionbelt, a driving ,8. In a machine of the character described, wheel for said belt, ,a plurality of load-susthe combination of: a base frame; a head taining wheels running on said belt, shafts frame supported thereby and rotatable with (one of them being hollow) for- 'ournally respect thereto; traction means supporting mounting said load-sustaining whee ,alever. the .base frame; means to swing the "head pivoted on the outer end of one of these shafts framerelative to the base frame, said means and actuated by means within the shaft,a drive-shaft, and a clutch between said base frame and of a rotatable pinion dependdrive-shaft and said driving wheel at the ing from the head frame and directly engageonter side of said unit, said clutch being actuted by said lever.

frame; mechanism to swing the head hollow consisting of a circular rack carried by the having-a member, located on the base frame,

frame, and engaging the rack; a rack, carried by the base frame, and rockable into and frame relative to the baseframe, consisting a In a circular rack carried'by the base frame,

hich does not include the rotation pf the able with the rack; and steering mechanism.

and directly and releasably engageable with I.

said depending pinion, for rendering the Steering mechanism responsive to the rotation of the pinion. Y

- 9. In a machine having a base frame, a head frame rotatably supported thereby, and

power actuated steering means; a steering mechanism therefor, com r1s1n'g: a steerlng lever carried by said base rame; a rack asso ciated with said lever; a .driving pinion car-- ried by said head frame; means for effecting a relative shifting between said rack and pinion into and out of intermeshing' engagement; and manually operated means for swinging said lever, otherwise than through said pinion.

10. a In a machine of the character described,

' the combinationof: a base frame; a head the base frame; steering mechanism; means frame supported'thereby and rotatable with respect thereto; traction means supporting for actuating said steering mechanism; a pinion, depending from the head frame and directly engaging a rack carried by the base frame, whereby to rotate the head frame; and

f means whereby the rotation of the pinion can respect t atuwill be used to operatethe'means for actuatin said steering mechanism,, otherwise than rough the rotation of the head'frame,

and otherwise than by means passing through the axis of rotation of the'head frame.

11.. In a machine of the character described, the combination of a base frame; a head frame supported thereby and rotatable with ereto; traction means supporting" the base frame; meansto swing the head frame relative to the base frame,,.sa id means consisting of a circular rack carried by the respect thereto .the base frame; steering mechanism on the base frame and of a rotatable pinion depending from the head frame and engageable with rack associated with said lever; a driving pinion carried by said head frame; and means for effecting a relative shiftin between said rack and pinion into and out o intermeshing engagement. 1

. 13. In a machine of the character described the combination of: a base frame; a head frame supporte l-therebyand rotatable with traction means supporting base frame associated with the traction .means; a pinion, depending from'the head frame, whereb to rotate the, head frame with respect to the ase frame; a rack on the base frame,.so contrived and adapted as to be mov-' able at will with respect tothe base frame by the rotation of'the pinion; and means opera,- tively connecting t 's rack to the steering mechanism, so as to render the mechamsm responsive to the mgvement of e rack, and thus to the rotation o the pinion.- p

In witness whereof, I hereunto subscribe my name. 5

svmn awJmBaGna.

to lever carried by. said base frame; avconcave 

